The invention relates to a tracked vehicle, in particular, an agricultural tracked vehicle, and to a method for determining the state of wear and/or the service life of at least one track belt of a tracked vehicle.
A tracked vehicle within the scope of the invention is understood to be any form of vehicle comprising a crawler track assembly and, if necessary, an additional wheeled travel mechanism. A tracked vehicle comprises, in particular, a separate ground drive for generating a propulsion, although it can also be a non-driven vehicle, for example, a trailer. Although there is a plurality of different applications which are encompassed by the present invention, the focus in the following is on tracked vehicles for carrying out agricultural work, which are referred to here as agricultural tracked vehicles. Tractors and self-propelled harvesting machines, such as combine harvesters or forage harvesters, are mentioned merely by way of example.
Vehicles of this type can be designed as a tracked vehicle or a half-track vehicle. Half-track vehicles comprise a crawler track assembly including at least one track-laying unit, in particular including two track-laying units positioned opposite one another relative to the vehicle longitudinal axis (direction of travel). The track-laying units each comprise, in turn, several rollers which are connected to one another via a revolving track belt in the form of a moving belt or a track chain. For example, track-laying units are known, which comprise a drive roller driven by the ground drive, a guide roller, and land rollers situated therebetween. In another variant, the so-called triangular traction unit, the track-laying unit comprises two guide rollers and a drive wheel situated above these, in the center. The focus here is to be on the variant of a vehicle comprising a rubber track.
Crawler track assemblies are often utilized on agricultural vehicles which have a high axle load. In this case, the wear of the outer lugs of the track belts, which are also referred to as track pads in the case of track chains, is one of the decisive criteria for the end customer, since the service life is mostly shorter than is the case with wheeled travel mechanisms, and the parts costs are comparatively high. The user generally assumes that the wear is linear and generally replaces the track belt before the start of the usage campaign, in order to avoid downtimes during the campaign. The wear is often not linear, however, due, inter alia, to the upwardly tapering shape of the outer lugs, but rather, for example, is degressive, i.e., the wear decreases as the duration of use increases. It is definitely possible, therefore, that the user will replace a track belt before an upcoming campaign, even though the track belt could have been utilized during the entire campaign.
Since it is difficult for the user to determine the optimal point in time to replace the track belts, it is known from the related art, on which the present invention is based, to determine the remaining service life with the aid of specific wear diagrams from the belt manufacturer. For this purpose, the user must manually measure the height of the outer lugs and then enter the value over the number of operating hours in a nomogram. On the basis of the comparison of several measured values, the user can then predict the remaining service life. This method is complex and susceptible to error, however.
It is also known from the related art to provide temperature sensors in tires of a vehicle, which wirelessly transmit a temperature signal which can be used as a piece of driver information in order to avoid a critical state of wear. An integration of appropriate sensors into a track belt is complex and costly, however. In addition, such sensors are subject to considerable loads during operation and, therefore, can also fail or yield incorrect measured values.